Apurba Sutradhar1, Daryl Arnall1, Ma. Lourdes s. Edano1, Muaid Ali2, Kefyalew Girma Desta3 and Jagadeesh Mosali4, (1)Plant and Soil Sciences, Oklahoma State University, Stillwater, OK (2)Oklahoma State University, Stillwater, OK (3)Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA (4)The Samuel Roberts Noble Foundation, Ardmore, OK
Foliar fertilization is useful during the critical time of crop development when soil application fails to meet the nutrients demand. Traditional P fertilizers contain phosphate (PO43-) which is not much reactive and thus mineralization in the soil is slow. Chemically phosphite (PO33-) is more reactive than phosphate. Breakdown of phosphite to plant available form is rapid due to its chemical bonding and instability. We hypothesized that foliar application of phosphite will improve corn grain yield and P concentration in plant tissues. The main objectives of this study were to evaluate the effects of foliar phosphite fertilization on growth and yield of corn. In 2011 a study was established comprised of 13 combination of two foliar phosphite application timing with traditional rates of both N and P fertilizers. Foliar phosphite application times were V6 and VT growth stages. A commercial phosphite solution was used which contains 20% P2O5 by volume. No significant differences were found in leaf and stem P concentration regardless any treatments. Also, P concentrations did not differ in grain in terms of single and double foliar phosphite application with basal N and P. N applied with basal P and phosphite generally resulted higher grain yield than P and phosphite applied without N. There was not significant yield response to the phosphite P fertilizer in combination with phosphate and nitrogen at 100% and 75% sufficiency of crop need. The greater yield was obtained due to N fertilizer. Grain N and P uptake was not significantly different between treatments when phosphite P was applied with basal N and P. Also, no differences were found with the treatment when N and P were less than 100% sufficient and foliar phosphite applied at V6 stage. Based on the results obtained, we concluded that, foliar phosphite have no significant contribution for the supply of P through leaf.